644325733 has 8 divisors (see below), whose sum is σ = 665106552. Its totient is φ = 623722176.

The previous prime is 644325709. The next prime is 644325751. The reversal of 644325733 is 337523446.

644325733 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 345104929 + 299220804 = 18577^2 + 17298^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644325733 - 2⁹ = 644325221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644325692 and 644325701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644325233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36910 + ... + 51487.

It is an arithmetic number, because the mean of its divisors is an integer number (83138319).

Almost surely, 2^644325733 is an apocalyptic number.

It is an amenable number.

644325733 is a deficient number, since it is larger than the sum of its proper divisors (20780819).

644325733 is a wasteful number, since it uses less digits than its factorization.

644325733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88631.

The product of its digits is 181440, while the sum is 37.

The square root of 644325733 is about 25383.5721087478. The cubic root of 644325733 is about 863.7110824712.

The spelling of 644325733 in words is "six hundred forty-four million, three hundred twenty-five thousand, seven hundred thirty-three".